PROGNOSTIC UTILITY OF SERUM ALPHA-N-ACETYLGALACTOSAMINIDASE AND IMMUNOSUPPRESSION RESULTED FROM DEGLYCOSYLATION OF SERUM GC PROTEIN IN ORAL-CANCER PATIENTS

Vitamin D-3-binding protein (Cc protein), a serum glycoprotein, is the precursor for the macrophage activating factor, Cancer patient sera c ontain alpha-N-acetylgalactosaminidase that deglycosylates Gc protein, Deglycosylated Cc protein cannot be converted to macrophage activatin g factor, leading to immunosuppression, Of 46 oral cancer patients wit h squamous cell carcinoma, approximately 22% had greatly reduced precu rsor activities, The precursor activity of approximately 61% of these patients was moderately reduced, The remaining patients (17%) had prec ursor activities equivalent to those of healthy humans, Patients with low precursor activity of serum Cc protein had high serum alpha-N-acet glgalactosaminidase activity, In contrast, patients with high precurso r activity had low serum alpha-N-acetylgalactosaminidase activity. Thu s, levels of serum alpha-N-acetylgalaetosaminidase of individual patie nts have an inverse correlation with precursor activities of their ser um Gc protein, Surgical removal of tumors resulted in a subtle decreas e in serum alpha-N-acetylgalactosaminidase activity with concomitant i ncrease in the precursor activity of serum Gc protein, Serum enzyme an alysis of nude mice transplanted with a human oral squamous carcinoma cell line revealed that serum alpha-N-acetylgalactosaminidase activity is directly proportional to tumor burden. Thus, alpha-N-acetylgalaeto saminidase activity in patient bloodstream can serve as a diagnostic/p rognostic index.